Three-prong τ decays with charged kaons

• Published in: The European physical journal. C, Particles and fields Particles and fields, 1998-03, Vol.1 (1-2), p.65-79
• Main Authors: Barate, R., Buskulic, D., Decamp, D., Ghez, P., Goy, C., Lees, J. -P., Lucotte, A., Minard, M. -N., Nief, J. -Y., Pietrzyk, B., Casado, M. P., Chmeissani, M., Comas, P., Crespo, J. M., Delfino, M., Fernandez, E., Fernandez-Bosman, M., Garrido, Ll, Juste, A., Martinez, M., Merino, G., Miquel, R., Mir, Ll. M., Padilla, C., Park, I. C., Pascua, A., Perlas, J. A., Riu, I., Sanchez, F., Teubert, F., Colaleo, A., Creanza, D., de Palma, M., Gelao, G., Iaselli, G., Maggi, G., Maggi, M., Marinelli, N., Nuzzo, S., Ranieri, A., Raso, G., Ruggieri, F., Selvaggi, G., Silvestris, L., Tempesta, P., Tricomi, A., Zito, G., Huang, X., Lin, J., Ouyang, Q., Wang, T., Xie, Y., Xu, R., Xue, S., Zhang, J., Zhang, L., Zhao, W., Abbanco, D., Alemany, R., Becker, U., Bazarko, A. O., Bright-Thomas, P., Cattaneo, M., Cerutti, F., Dissertori, G., Drevermann, H., Forty, R. W., Frank, M., Hagelberg, R., Hansen, J. B., Harvey, J., Janot, P., Jost, B., Kneringer, E., Knobloch, J., Lehraus, I., Lutters, G., Mato, P., Minten, A., Moneta, L., Pacheco, A., Pusztaszeri, J. -F., Ranjard, F., Rizzo, G., Rolandi, L., Rousseau, D., Schlatter, D., Schmitt, M., Schneider, O., Tejessy, W., Tomalin, I. R., Wachsmuth, H., Wagner, A., Ajaltouni, Z., Barrès, A., Boyer, C., Falvard, A., Ferdi, C., Gay, P., Guicheney, C.
• Format: Article
• Language: English
• Subjects: Charged particles; High Energy Physics - Experiment; Kaons; Particle decay; Physics
• ISSN: 1434-6044; 1434-6052
• DOI: 10.1007/BF01245798

Final states with charged kaons in three-prong τ decays are studied by exploiting the particle identification from the dE/dx measurement. The results are based on a sample of about 1.6 × 105 detected τ pairs collected with the ALEPH detector between 1991 and 1995 around the Z peak. The following branching ratios have been measured: B(τ- → K−K+π−ντ) = (1.63 ± 0.21 ± 0.17) × 10−3, B(τ− → K−π+π−ντ) = (2.14 ± 0.37 ± 0.29) × 10−3, B(τ− → K−K+π−π0ντ) = (0.75 ± 0.29 ± 0.15) × 10−3, and B(τ− → K−π+π−π0ντ) = (0.61 ± 0.39 ± 0.18) × 10−3. The first two measurements are more precise than the current world averages, while the last two channels are investigated for the first time. The 95% C.L. upper limit on the branching ratio for the decay τ− → K−K+K−ντ is 0.19 × 10−3. A study of intermediate states occurring in the K−K+π−ντ and K−π+π−ντ decays is also presented.